Tool change systems for painting robots, whose atomizer is fastened to a flange that forms the releaseable part, which is secured by pneumatic forces on a machine flange forming the fixed part, are state of the art. To release the atomizer, an air connection is operated by the robot itself for opening of a closure cylinder of the atomizer change device of the robot. This air supply by the robot itself can lead to unintentional release of the atomizer possibly during the coating operation during improper control, which not only results in mechanical damage and failure of the coating unit, but also results in an inadmissible hazard of explosion by separation of the electrical connections of the electrostatic atomizer.